Unfortunately, VS2008 SP1 doesn't recognize C++ tr1 headers. That means there are no syntax highlighting and no intellisense for these files.
This is a bug, but you can fix it by yourself. The trick is in the registry. VS maintains a list of extensionless files, and will treat them as cpp files.
It is under: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\9.0\Languages\Extensionless Files\{B2F072B0-ABC1-11D0-9D62-00C04FD9DFD9}
Just add tr1 headers into it and you'll now get full support of new tr1 features. Here is the reg file:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\9.0\Languages\Extensionless Files\{B2F072B0-ABC1-11D0-9D62-00C04FD9DFD9}]"array"="""random"="""regex"="""tuple"="""type_traits"="""unordered_map"="""unordered_set"="""xawrap"="""xawrap0"="""xawrap1"="""xawrap2"="""xfwrap"="""xfwrap1"="""xrefwrap"="""xtr1common"="""xxbind0"="""xxbind1"="""xxcallfun"="""xxcallobj"="""xxcallpmf"="""xxcallwrap"="""xxfunction"=""'xxmem_fn"="""xxpmfcaller"="""xxrefwrap"="""xxresult"="""xxtuple0"="""xxtuple1"="""xxtype_traits"=""